概述
coding:utf-8!
chapter 7 用户输入和while循环
函数input()提示用户输入内容
运用while循环控制程序运行时间
message = input("Tell me something, and I will repeat it back to you: ")
print(message)
print("n")
sublime text代码编辑器
name = input("Please enter your name: ")
print("Hello, " + name + “!”)
print("n")
prompt提示
prompt = “If you tell us who you are, we can personalize the messages you see.”
prompt += "nWhat is your first name? " # +=将后面的字串符加在prompt末尾(这句可省略)
注意:上面不能写成:print(prompt + "nWhat is your first name? ")
name = input(prompt)
print("Hello, " + name + “!”)
需要记住prompt的上下文用法
print()
使用int()获取数值输入
age = input("How old are you? ")
age = int(age) # int()将数字的字串符转换为数值表示
if age >= 18:
print(“True, it is larger than 18.”)
else:
print(“False, it is smaller than 18.”)
print()
判断一个人是否满足过山车身高要求
height = input(“How tall are you, in inches?”)
height = int(height)
if height >= 36:
print("nYou’re tall enough to ride!")
else:
print("nYou’ll be able to ride when you’re a litter older.")
print()
求模运算符%将2个数相除并返回余数
print(4%3)
print(5%3)
print(6%3)
print(7%3)
print()
利用求模运算符%判断奇偶数
number = input("Enter a number, and I’ll tell you if it’s even or odd: ")
number = int(number)
if number % 2 == 0:
print(“The number " + str(number) + " is even.”)
else:
print(“The number " + str(number) + " is odd.”)
如果用的是Python2.7,需要用函数raw_inpu()来代替Python3里面的input(),否则会错误
for循环针对集合中每个元素的一个代码块
while循环会不断运行直到条件不满足为止
print()
使用while循环数数
current_number = 1
while current_number <= 5:
print(current_number)
current_number += 1
让客户选择何时退出
prompt = "nTell me something, and I will repeat it back to you1original: "
prompt += "nEnter ‘quit’ to end the program. "
message = “” # 创建变量message,用于存储用户输入值
while message != ‘quit’: # ‘!=’ 表示‘不等于’ # 将message与quit比较
message = input(prompt)
print(message)
print()
使用if语句修复上面程序(不打印quit)
prompt = "nTell me something, and I will repeat it back to you2if: "
prompt += "nEnter ‘quit’ to end the program. "
message = “”
while message != ‘quit’:
message = input(prompt)
if message != ‘quit’:
print(message)
使用标志(很多条件都满足才继续运行,可定义一个变量来判断活动状态)
prompt = "nTell me something, and I will repeat it back to you3true: "
prompt += "nEnter ‘quit’ to end the program. "
active = True
while active:
message = input(prompt)
if message == ‘quit’:
active = False
else:
print(message)
使用break退出循环(立即退出while循环不再运行余下代码,也不管结果如何时使用)
prompt = “nPlease enter the name of a city you have visited: 4”
prompt += "n(Enter ‘quit’ when you are finished.) "
while True: # 以while true打头的循环将不断运行,直到遇到break语句
city = input(prompt)
if city == ‘quit’:
break
else:
print("I’d love to go to " + city.title() + “!”)
print()
在循环中使用continue
current_number = 0
while current_number < 10:
current_number += 1
if current_number % 2 == 0:
continue # 如果可以被2整除,就直接返回循环开头
print(current_number)
print()
避免无限循环
x = 1
while x <= 5:
print(x)
x += 1 # 如果没有这行代码,循环将没完没了地打印1。可按Ctrl+C停
使用while循环处理列表和字典
在列表之间移动元素
print()
首先,创建一个待验证用户列表 和 一个用于存储已验证用户的空列表
unconfirmed_users = [‘alice’, ‘brian’, ‘candace’]
confirmed_users = []
验证每个用户,直到没有未验证用户为止
将每个经过验证的列表都移到已验证用户列表中
while unconfirmed_users:
current_user = unconfirmed_users.pop()
print("Verifying user: " + current_user.title())
confirmed_users.append(current_user)
显示已验证的用户
print("nThe following users have been confirmed: ")
for confirmed_user in confirmed_users:
print(confirmed_user.title())
删除包含特定值的所有列表元素
print()
pets = [‘dog’, ‘cat’, ‘dog’, ‘goldfish’, ‘cat’, ‘rabbit’, ‘cat’]
print(pets)
while ‘cat’ in pets:
pets.remove(‘cat’)
print(pets)
使用用户输入来填充字典
print()
responses = {}
设置一个标志,指出调查是否继续
polling_active = True
while polling_active:
# 提示输入被调查者的名字和回答
name = input("nWhat is your name? ")
response = input("Which mountain would you like to climb someday? ")
# 将答案存储在字典中
responses[name] = response
# 看看是否还有人要参与调查
repeat = input(
"Would you like to let another person to respond?(yes/no) ")
if repeat == ‘no’:
polling_active = False
调查结束,显示结果
print("n— Poll Results —")
for name, response in responses.items():
print(name + " would like to climb " + response + “.”)
最后
以上就是英俊太阳为你收集整理的Python编程:从入门到实践(读书笔记:第7章 用户输入和while循环)coding:utf-8!chapter 7 用户输入和while循环函数input()提示用户输入内容运用while循环控制程序运行时间sublime text代码编辑器prompt提示注意:上面不能写成:print(prompt + "\nWhat is your first name? ")需要记住prompt的上下文用法使用int()获取数值输入判断一个人是否满足过山车身高要求求模运算符%将2个数相除并返回余数利的全部内容,希望文章能够帮你解决Python编程:从入门到实践(读书笔记:第7章 用户输入和while循环)coding:utf-8!chapter 7 用户输入和while循环函数input()提示用户输入内容运用while循环控制程序运行时间sublime text代码编辑器prompt提示注意:上面不能写成:print(prompt + "\nWhat is your first name? ")需要记住prompt的上下文用法使用int()获取数值输入判断一个人是否满足过山车身高要求求模运算符%将2个数相除并返回余数利所遇到的程序开发问题。
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